After a perfectly-scripted joke from the Labour leader on alcohol pricing, the PM never recovered.

Rarely has Ed Miliband enjoyed PMQs as much as he did today. He began with what sounded like a deathly dull question on minimum alcohol pricing before producing his best opening line to date: "is there anything he could organise in a brewery?"

After Vince Cable's intervention on the economy, the OBR's rebuke of Cameron, Theresa May's barely concealed leadership pitch and new forecasts of a triple-dip recession, the Labour leader was not short of material for the rest of the session. "When the Business Secretary calls for him to change course," he asked the PM, "is he speaking for the government?" After Cameron noted in his response that car manufacturing, at least, was up, Miliband ad-libbed: "never mind more car production, it's taxi for Cameron after that answer". Things had got so bad, he noted, that No. 10 had sent Baroness Warsi (the woman he sacked as Conservative chairman and no friend of Cameron) out to say that she had "full confidence" in the PM.

An off-form Cameron resorted to his stock lines: Miliband had nothing to say about the deficit, Labour would borrow more, Ed Balls was still shadow chancellor, the party was in hock to union "dinosaurs". All of these fell flat, with Tory MPs entirely unmoved.

The well-marshalled Labour benches again targeted Cameron with questions over the "bedroom tax" and whether he will gain from the abolition of the 50p rate. To the former, he replied by again declaring that only Labour could call "a welfare reform a tax". But with the phrase ("bedroom tax") firmly lodged in the public consciousness, Cameron needs to spend more time defending the measure itself, rather than arguing over the name. On the 50p rate, for the third week running, Cameron again refused to say whether he would benefit from the move, merely stating that he would "pay everything has to". But Labour, encouraged by how Barack Obama forced Mitt Romney onto the defensive over his tax bill, intends to keep pressing the PM on this subject.

The session ended surreally with Cameron reading out an imaginary letter from "Ed who lives in camden" asking what he should do about the government's seven per cent stamp duty charge on £2m houses. The gag finally roused the Tory benches as the PM mocked Labour's "champagne socialist" (although Cameron, for reasons that do not need stating, is ill-suited to class politics) but their earlier silence means it was Miliband who left smiling.